氣軔系統概述

所有鐵路車輛都安裝有機械式軔機，即機械式煞車。運作方式為透過手動操作手軔機，或以壓縮空氣推動閘瓦，物理性地使其擠壓車輪。

使用壓縮空氣緊軔較為迅速，因此部分車輛載有單獨車輛制軔方式，而不僅依賴手軔機。更重要的，使用壓縮空氣得以使整組列車中的所有軔機同步緊軔，此稱貫通制軔。構成氣軔系統的主要部件為：

主風缸

主風缸是動力車輛上搭載的大容量氣瓶。此容器儲有空氣，且通常以車輛搭載之風泵加壓至 8 Bar 。主風缸為氣軔系統的壓力來源，同時也供應如喇叭和雨刷等其他車輛系統。

軔管

軔管是用於分配壓縮空氣至整組列車的管路系統。正確連結的列車中，車輛之間以軟管連結且氣軔角旋塞必須開啟，而列車兩端之氣軔角旋塞則維持關閉。此使整組列車的軔管在正常情況下被作用中的主風缸充至 5 Bar 壓力。軔管容納的空氣量相對要少，但加掛愈多車輛仍將提高空氣用量。

輔助風缸

輔助風缸是全數獨立車輛上搭載的中等容量氣瓶。它們隨著軔管充氣，在需要時以當中儲存的壓力為單獨車輛緊軔。取決於列車中的車輛數，為它們充氣可能需要一段時間，但壓力在運作期間幾乎不會被消耗殆盡。

軔缸

軔缸是全數獨立車輛搭載的低容量氣缸，為實際施加制動力、驅動軔機的機構。當輔助風缸對其加壓，軔缸內機構將推送閘瓦推擠車輪，導致車輛減速。

在必要時刻，軔缸內的壓力可以被手動釋放。

司軔閥

無論是單獨或貫通制動方式，通常皆透過動力車輛駕駛室內，有著操縱桿的司軔閥操作。司軔閥有著不同運作方式，且必須在司軔閥隔離旋塞正確開關時才能發揮作用。

Train Charging

Due to leaks , no brake components can remain pressurized indefinitely. It usually takes some time to bring the components of unused vehicles to their nominal, high pressure level, before they can be set in motion. The two biggest factors are the main reservoirs, which will charge as quickly as the respective compressor(s) allow it, and auxiliary reservoirs, which may take a long time to charge, depending on how many vehicles there are in the train.

Adding additional locomotives to the train to improve charging speeds is a viable option, and so is revving the engine .

Automatic Stop Safety Mechanism

Crucial safety feature of the compressed air brake system is that, in case a vehicle connection is severed, such as due to a derailment , emergency brakes are automatically applied on both remaining train parts. This is because the brake pipe pressure is lost to the atmosphere, and it is integral to the compressed air brake system design in trains.